Recently, a number of weeds normally not observed in various regions of Japan were found, and control thereof is a problem to be solved. Generation of these weeds is thought to be a result of mixing of seeds of the weeds into imported cereals and disseminating them to the fields as a compost of feces of domestic animals that ate the cereals. The potential for transmission of morning glory spp. seeds makes this a potential problem throughout the world where desired plants are at risk of being destroyed by morning glory spp. Morning glory spp. as one of these weed species are strongly harmful weeds which are vine-like and coil around crops and trees, and which, in some cases, reach several meters in length.
Morning glory spp. can be often observed in soybean fields, paddy field ridge, orchards, dry fields, farm roads, roadsides and the like in Ishikawa, Aichi, Mie, Gifu and Shizuoka prefectures, Tokyo, Chiba prefecture and the like.
For example, in the Tokai region, in soybean fields and some orchards showing generation of morning glory spp. as the most serious problem, there are recognized generations of Ipomoea hederacea Jacq., Ipomoea hederecea Jacq. var. integriuscula A. Gray, Ipomoea triloba L., Ipomoea lacunosa L., Ipomoea coccinea L., Ipomoea purpurea Roth and Ipomoea nil Roth. Soybean cultivation in the Tokai region is often carried out with large scale by farming associates and large scale farmhouses, and when morning glory spp. prevail in soybean fields and coil around soybean, their control is extremely difficult, and there is no other choice than discard of harvest in some cases. In the case of orchards, when morning glory spp. coil around trees and extend to sites over human reach, their control is extremely difficult.
Various problems due to the generation of morning glory spp. include (i) the germination term of morning glory spp. lasts over a long period, and hence even if they are once controlled, new morning glory generate, (ii) the activities of soil-treating herbicides and selective foliar application herbicides for leaves on morning glory spp. are low, (iii) herbicidal activities of non-selective foliar application herbicides on morning glory spp. differ among herbicides, (iv) difficulty spreading non-selective foliar application herbicides to inter-ridge areas (areas/furrows between ridges of soybean patches) during soybean growth period, and the like.
Citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention.